Loud-speaker



Y April 29,1930; A '1). E. KIERNAN' 1,756,201 I LOUD SPEAKER Filed Deeps, 1927 W MW Patented Apr. 29, 1930 UNITED STATES PAT-ET Eric JOHN E. KIERNAN, BROOKLYN, NEW YORK LoUn-srEAKEn Application filed December a, 192?. Serial a. 238,732

The invention relates to sound reproduction devices used in connection with radio rebetween three electromagnets mounted in atriangular frame.

Fig. 2 is a side view of one of the electromagnets attached to the diaphragm.

In Fig, 1 three electromagnets are shown spaced at approximately e ual intervals from one another, but any num er, from two up,

may be used, supported in a frame of appropriate shape. Y

' By electromagnet I mean a speaker unit or telephone receiver, of the two-pole type or of the four-pole and In any case, middle point on a sharp pivot.

The invention involved a study of the prin; ciple known in physics as the parallelogram of forces. A force being completely specified by (a) its magnitude, (5) its point of application, and (0) its direction, it became necessary for me to determine, more exactly than has heretofore been done, the means by which a diaphragm could be made to vibrate perpendicularly to its plane with a minimum of transverse vibrations and with suihcient magnitude to convey its vibrations to the air at a distance. F is. a frame to support the device.

M is an electromagnet; A, its armature extending on both sides of To' increase the effect of the vibrations of the armature A in each case, electromagnets M by sions -.A an angle with the armature proper A for the purpose of changing the directlon of the v1 brations and having the force of same strike against the diaphragm D at a reduced angle.

adding angular extenpolarized armature type. stantly inthe same phase of vibration,

the armature is supported at its.

1 have lengthened it beyond the i d A \The extensions form an Points 1 and 2 are sockets in which X and T move freely. X and Y are rods or wires attached from the armature sockets 1 and 2 .to similar sockets 3 and 4 in the actuating pin flanges O.- X and Y are preferably tangential to the vibrations of the armature at points 1 and 2.

B is a subsidiary actuating pin to make the actuation of the diaphragm D more uniform over its entire area, and rests against a plate S made of some hard material foire-inforcing the said diaphragm at that point.

C is a similar pin on the opposite side of the diaphragm D, and rests a ainst a rubber pad T to .stabilize the diap ragm at that point and at'the same time allow the vibrations of the armature extensions A and A to be communicated to thepin ing unduly absorbed by pins B and C.

The diaphragm D is balancedbetween the electromagnets, and the plane of said dia-. phragm is at right angles to the armatures A of the said electromagnets. All the A ex tensions of the various armatures .are conand all the A extensions on the opposite side of the diaphragm D are as a unit in the opposite phase with respect to the A extensions. The resultant of thesevibra'tions lies in a direction perpendicular to the diaphragm D.

As to variations:

The diaphragm maybe of wood, bakelite, glass, hard rubber, compressed paper, etc, and if of wood should be composed of a number of sectors with the grain running in different directions to give the greatest possible inflexibility to the diaphragm.

The actuating pin P may be attached to the diaphragm D by any suitable method, or instead of a single actuating pin in the centre, a plurality may be used for attaching the several armature connectors X and Y in .pairs to the diaphragm, D which is then strongly reinforced, as shown in the figures. The use of one pin P, however, is preferable.

A and A may beextended upward to meet P without bethe central portion. of 7 an elongated pin P, the X andYconnectors being eliminated and points 1 and 3, 2 and 4:-

phragm.

being connected to make simple free-moving Again, A and A may be'dropped at an angle below'A, in which case the pin P should vbe still more elongated to form the proper angle with the X and Y connectors; pins B and C being eliminated, for the movement of X and Y is in the direction of their length, and at a considerable angle to the plane 0 D.

As shown in Figure 2, the armature A is.

between the diaphragm D and .the pivot N; and the connectors X and Y are properly 1 rods; but if the pivot N is placedbetween the armature A and the diaphragm D, then X and Y may be of light wire or string.

R is merely a band, enclosing the armature D, and is made of any suitable material; it serves to give direction to-the sound waves; and is either attached to the edge of diaphragm D or in close proximity thereto.

Claims:

I 1. In a loudspeaker, a'diaphr'agm, a plu- I rality of electromag'nets arranged around said diaphragm, armatures for said electromagnets, and angular extensions at each end of said armatures for communicating vibrations to said diaphragm.

2. In a loud speaker, a diaphragm, a plurality of electromagnets arranged around said diaphragm, armatures for said electromagnets, connections from said armatures on each side of said diaphragm to a central actuating pin and additional actuating ins from said armature to various points 0 said dia- JOHN E. KIERNAN; 

